assert.md

Assert in Python testing

The assert keyword is used to perform a runtime assertion check. It allows you to test whether a certain condition is True, and if the condition is not met, an AssertionError exception is raised, which can help you identify issues or bugs in your code during development and testing.

The syntax of the assert statement is as follows:

assert condition, message

Here, condition is the expression you want to check, and message is an optional string that you can provide to give more context about the assertion failure. The condition should evaluate to True for the code to continue executing normally. If the condition is False, Python raises an AssertionError with the provided message (or a default message if none is given).

Here's an example of how you might use the assert statement:

def divide(a, b):
    assert b != 0, "Division by zero is not allowed"
    return a / b

result = divide(10, 0)
print(result)

In this example, the assert statement checks if b is not equal to zero before performing the division. Since b is 0, the condition is False, and an AssertionError is raised with the specified message: "Division by zero is not allowed".